CPU and Architecture

The Xtreamer comes with a Realtek RTD1283 32 bit MIPS (Release 2) CPU. The RTD1238, also called 'MARS', is an enhanced PBGA (Ball Grid Array) version of the RTD1073, or 'VENUS', chip, which is part of the 'Galaxy' family of Realtek SoCs.

Overview

The RTD1073/1283 represents Realtek’s third generation media processing technology and incorporates three major HD specifications.

RMVB HD Support: RMVB (RealMedia Variable Bitrate) is a multimedia container format developed by RealNetworks. Widely used in Asia and the Chinese market, the RMVB playback requirement has been raised to 720P (1280*720).

Board Layout

Datasheet

The first generation Xtreamer is very close to the original Realtek RTD1073 Demo Board layout, whose datasheet can be downloaded here

Pictures

Xtreamer

(Picture credits: Pawel)

Xtreamer Pro

Interfaces

Serial

Both the Xtreamer and Xtreamer Pro include a 4 pin serial port on the motherboard, located near the fan connector. As this port uses 3.3V TTL signals, a converter, like the MAX232, must be used before you can connect to a PC RS232 port.

This serial port, which is directly linked to UART0 on the CPU, can be used to access the embedded Yamon Bootloader as well as the internal Linux console.

On the Xtreamer, the serial port is labelled J2 and uses a standard 2.54mm spaced 4 pin connector

On the Xtreamer Pro, the serial port is labelled J1 and uses a Molex PicoBlade connector. It is however possible to use the cable connecting the faceplate USB, to access this UART more easily, as illustrated here

EJTAG

On the Xtreamer, the port labelled T1 can be used for EJTAG access. It uses the same pinout as described on page 6 of the RTD1073 demo board datasheet
On the Xtreamer Pro, EJTAG access does not appear to be available.

IR Remote

The Xtreamer uses a standard infrared remote. For the list of programmable IR codes, as sent by the remote, see the IR_Codes page.

Yamon Bootloader

If you have a serial connection to UART0 (115200n8r), the Yamon Bootloader can be accessed by pressing 'Esc' while booting the device.

This custom version of the MIPS Bootloader uses slightly modified command names, as they must either be prefixed by 'xx' (eg. 'xxcontinue') or have their first letter replaced by 'x' (eg. setenv -> xetenv).

Bootloader Recovery

The RTD chip provides Bootloader update facility through serial using the YModem protocol. To enter the Bootloader Serial Recovery console, you need to press the Space Bar in your serial console while the unit boots. The bootloader recovery mode is accessible even if the Yamon bootloader or the whole flash has become corrupted.
To be able to update the bootloader, one must provides a HW register settings file ("s"), to setup Flash memory access, as well as a bootloader dump file ("d"), and a serial recovery application for the flash. The rtdsr recovery utility can be used for such a purpose. Additional information can also be found here.